The disclosure of the following priority application is incorporated herein by reference: Japanese Patent Application No. 2002-271150 filed Sep. 18, 2002
1. Field of the Invention
The present invention relates to a flash apparatus on which an auxiliary battery apparatus can be mounted and the auxiliary battery apparatus.
2. Description of the Related Art
There are flash apparatuses for cameras in the related art, with which auxiliary battery apparatuses can be used (see, for instance, Japanese Laid Open Patent Publication No. S61-171099). Such. use of an auxiliary battery apparatus mounted at a flash apparatus is enabled by linking the auxiliary battery apparatus to the flash apparatus main body so as to connect the batteries in the auxiliary battery apparatus in parallel to or in series with the batteries in the flash apparatus.
The battery power in a flash apparatus can be checked based upon the speed at which the main capacitor is charged. The battery check can be achieved by judging that there is a sufficient level of battery power remaining if the charge speed is high and judging that the available battery power is becoming depleted if the charge speed is low. The results of the judgment indicated at a display unit allows the user to ascertain at any time whether or not the batteries need to be replaced.
However, in the case of a battery check in a flash apparatus that allows the use of an auxiliary battery apparatus as described above, the level of available power remaining in the individual batteries corresponding to a given charge speed when the auxiliary battery apparatus is used is different from the level of the available power remaining in the individual batteries at the same charge speed when the auxiliary battery apparatus is not used, due to the difference in the number of batteries. Unless this issue is appropriately addressed, the remaining battery power of batteries nearing the end of their service life may be erroneously indicated as sufficient when the auxiliary battery apparatus is used, which may then lead to a problem of the user being caught unprepared for a sudden depletion of the batteries during operation. In addition, if a battery having reached the end of its service life is continuously used with charged batteries, that battery becomes reverse charged, and an internal gas is generated by the pole reversal phenomenon, resulting in a problem such as a liquid leak.
The flash apparatus according to the present invention comprises a light emission unit that emits light with an electric charge stored at a main capacitor, a battery chamber in which an internal battery constituting a source battery is loaded, a mounting unit at which an auxiliary battery apparatus having loaded therein an external battery to be connected in series with the internal batteries is detachably mounted and a detector that detects whether or not the auxiliary battery apparatus is mounted.
The flash apparatus further comprises a battery check circuit that detects a charge speed at which the main capacitor is charged and generates one of an output corresponding to remaining battery power available in the internal battery and an output corresponding to remaining battery power available in the internal battery and the external battery based upon the charge speed and results of a detection executed by the detector.
It is desirable that the battery check circuit be capable of generating the output corresponding to the remaining battery power by comparing the detected charge speed with a threshold value for battery check. The battery check circuit should raise the threshold value when the detector detects that the auxiliary battery apparatus is mounted compared to the threshold value set when the presence of the auxiliary battery apparatus is not detected. By varying the threshold value in this manner, it becomes possible to detect the remaining battery power with a high degree of accuracy both when the auxiliary battery apparatus is mounted and when the auxiliary battery apparatus is not mounted.
The auxiliary battery apparatus according to the present invention that can be detachably mounted at an electric apparatus comprises a battery loading unit that allows an external battery to be loaded therein and can be detachably mounted at the electric apparatus in place of a lid of a battery chamber of the electric apparatus, an electric connection member that connects an external battery loaded in the battery loading unit to an internal battery loaded in the battery chamber of the electric apparatus as the battery loading unit is mounted, and a lid mounting unit provided at the battery loading unit, to which the lid can be attached. In this auxiliary battery apparatus, the battery in the battery loading unit is concealed as the lid is attached at the lid mounting unit. Since the lid of the electric apparatus can be attached to the auxiliary battery apparatus, it is not allowed to go missing easily.
It is desirable that the auxiliary battery apparatus further include a lock mechanism which disallows removal of the battery loading unit from the electric apparatus by interlocking with attachment of the lid at the battery loading unit and allows the battery loading unit to be disengaged by interlocking with detachment of the lid.
The battery loading unit may include a battery support bed that supports the external battery and can be detachably mounted at the electric apparatus and a battery cover that is positioned and set so as to enclose the external battery supported by the battery support bed. As the battery cover is positioned and set at the battery support bed and the lid is attached at the battery cover, the battery support bed and the battery cover come to constitute an integrated unit via the lid, and as the lid is detached, the battery support bed and the battery cover become disengaged from each other, thereupon ceasing to constitute the integrated unit.
The electric apparatus may be, for instance, a flash apparatus for a camera.
A flash system or an electric system with auxiliary batteries according to the present invention may assume the following structure. Namely, the system comprises the flash apparatus or the electric apparatus described above and the auxiliary battery apparatus described above, the internal battery and the external battery are each cylindrical in shape, an internal battery space where a plurality of cylindrical batteries are loaded side-by-side in a row is formed at the battery chamber and an external battery space where a single cylindrical battery constituting the external battery is loaded so that the axis of the external battery extends along a direction of the row in which the plurality of cylindrical batteries are arranged is formed at the auxiliary battery apparatus.